TFB Review: The Primary Arms 1-8×24 Rifle Scope With ACSS Reticle

    Primary Arms 1-8x scope review

    The Primary Arms 1-8×24 rifle scope is a Low Power Variable Optic (LPVO) that uses the patented Advanced Combined Sighting System (ACSS) reticle. I was already familiar with Primary Arms’ 1-6x ACSS optic, having owned it for several years. I wanted to test out the newer Primary Arms 1-8x offering as well and Primary Arms kind enough to let me give it a go.

    Primary Arms 1-8x scope review

    The Primary Arms 1-8x rifle scope mounted to the author’s AR-15.


    When I bought my Primary Arms 1-6x scope, I also purchased their one-piece cantilever scope mount, so I used that same mount to cradle the 30mm tube of the 1-8×24. The Primary Arms 1-8x came with a smooth matte finish. The scope feels solid and the glass was clear and crisp. The turret caps are easily removed and replaced and the illumination dial has assuring clicks that are easily felt when selecting the desired brightness setting. The scope caps gave a satisfying positive flip open when a little pressure was applied to the tabs. The half-MOA turret adjustments can be made by hand and I could feel and hear them click into place at each adjustment. The magnification adjustment is a little stiff, but manageable. The diopter ring is easily adjusted to correct for near or farsightedness. The 1-8x scope is 10.75 inches long and just under 3 inches wide at the turrets. Primary Arms updated the ballistics capability to cover 5.56/.223, 5.45×39, .308 Win and 6.5 Grendel. The image through the glass is crisp and clear, however, my photographs don’t do it justice.

    Primary Arms 1-8x scope review

    Under the scope caps are the adjustment knobs for elevation and windage. There are also zero index cards that operate separately from the knobs.

    Primary Arms 1-8x scope review

    Viewing trees at 100 yards through the Primary Arms 1-8x rifle scope. No illumination was used in this photo.

    Each Primary Arms 1-8×24 scope comes with a battery installed for the reticle illumination dial on the left-hand side. Underneath the windage turret cap is a spare battery that’s secured in place, but easily removed when needed. I found this complementary battery handy since the scope had been left on from the factory somehow. The spare battery was called to action after I checked the scope over. The illumination settings are spaced at a nice gradual increment that goes to 11. I found that on a bright day, setting 11 was just right for a bright, fast reference for quick and close shooting without any red halo effect within the glass. At night, it seemed that setting 5 or 6 was just bright enough to be quickly picked up by the eye, but soft enough so as not to be distracting. On dark days, around dusk or just before dawn, settings 7-9 were just right for me, however, not everyone’s eyes are like mine and others may have different preferences.

    Primary Arms 1-8x scope review

    The illumination dial goes to 11. The magnification adjustment ring can be seen in the foreground.

    Primary Arms 1-8x scope review

    A look through the Primary Arms 1-8x scope on a rainy day. As mentioned, photographing the image clarity was difficult.


    One problem I encountered was self-induced. I prefer shorter, fixed stocks, and typically on an AR platform, I shoot with my nose to the charging handle. When I built my AR-15, I used a Rock River Arms “Entry” fixed stock. Which ended up being too short, so I added a thicker butt pad to add an extra inch to the length of pull. The eye relief of the 1-8x at the lower powers was fine. However, when I cranked the power to 8x, I was having to mash my nose to the charging handle just to get the right eye relief. With my choice of stock, it seemed to hinder my ability to get comfortable behind the scope and limited where on the top rail I could mount it. It should be noted that the vast majority of AR-15 stocks are adjustable and non-AR-15s have a longer stock comb to adjust to the eye relief at various power levels.


    The ACSS reticle has made quite a splash for Primary Arms. TFB covered the ACSS’s conception some time ago and the work that went into it. Primary Arms also made an arrangement with Trijicon to utilize the reticle in their famous ACOG optic as well. As you’ll see in the pictures below, the ACSS allows for ranging by width or height, depending on how the target presents itself. There are also moving target and windage dots for quick estimation holdovers. YouTuber TiborasaurusRex had an interesting interview with the designer of the ACSS reticle that you can listen to HERE. The reticle is in the second focal plane so that it stays the same size no matter what magnification the scope is set to.

    Primary Arms 1-8x scope review

    Width and height ranging options using the ACSS reticle. Image from Primary Arms’ website.

    Primary Arms 1-8x scope review

    Bullet Drop Compensator (BDC) and windage marks of the ACSS reticle. Image from Primary Arms’ website.

    Even though I’d already owned my Primary Arms 1-6x ACSS scope for a while, I really didn’t have access to a lot of yardage. Until I had the 1-8x in my hands, the farthest I’d ever shot was 300 yards, and not very many rounds at that. I decided that I would see what I was capable of at 500 yards using the 1-8x ACSS reticle. My friends at the Wapsi Sports Supply gun store were kind enough to let me use their land to stretch out my legs, literally.

    Primary Arms 1-8x scope review

    The view with my camera zoomed in all the way. The gun shop staff were helpful in checking the target for me.

    Primary Arms 1-8x scope review

    I dialed the scope up to 8x and followed Primary Arms’ instruction manual and zeroed the chevron at half an inch high for my Hornady 75 grain Match Steel Case ammo at 100 yards. My son helped me measure out another target at 500 yards. I again used the Hornady Steel Match ammo. I was fortunate in that I saw my first round hit the dirt a few feet in front of my target while holding the scope at the 500-yard mark on the drop compensator line. I immediately suspected that the listed velocity on my ammo was from a longer test barrel. I tried several different holds using the 600-yard mark at the bottom of the outlined “Q” target and at the shoulder as well. I also used Hornady’s 5.56 75 grain Frontier ammo when I ran out of the Steel Match. I ended up with a minute-of-man sized group, which I wasn’t thrilled about, but for my first time at 500 yards with a mil-spec AR trigger, I was happy to see what my baseline was and can improve from there. While my results are less stellar than what others are capable of, it didn’t discourage me from the Primary Arms 1-8×24. If anything, I saw it as a personal challenge to improve my accuracy.

    Primary Arms 1-8x scope review

    Target after the 500-yard range session.

    Next up was our department firearm qualification day. Since my department runs 55-grain ammo, I zeroed the scope using M193 ammo the day before. After zeroing at 100 yards, I aimed for the 8” steel targets at 200 yards and rang them with each shot. I kept the Primary Arms 1-8x scope on my rifle and qualified handily with it on the 50 yard CQB course using M193 55 grain ammo. Things were moving quickly that day so I didn’t get a picture of the target. The lighted horseshoe and chevron reticle made for quick acquisition on the timed 50 round course ranging from 50, 25, 15, 10 and 7 yards.


    I like LPVO’s, and the Primary Arms 1-8x optic is no exception despite the other variables I induced with the experience such as my short stock and using ammo that didn’t match the needed velocities for the ACSS reticle to work. The Primary Arms 1-8×24 scope, like other LPVO’s, allow a shooter to clearly see and engage targets in a wide range of distances and I believe that this optic can assist most shooters in getting the most out of their rifles. Being able to zoom from no magnification up to 8 times what the naked eye can see, while having a quick, lighted focal point to aim onto the target is an advantage that should be strongly considered. With an MSRP of $389.99, the Primary Arms 1-8×24 scope is an option that won’t break the bank.

    Finding that perfect load to match the ACSS reticle will be easiest for handloaders when it comes to the loads that need a specific velocity that is achievable in your barrel length. However, with more common loads such as M193 and M855, Primary Arms has worked out the math for several different barrel lengths. Thus, just spending some time with your set up and finding what works and what doesn’t is part of becoming more proficient. I plan to spend more time with the Primary Arms 1-8x scope and bring you an update in the future.

    I don’t always carry my own rifle while on duty, but there have been calls in which officers have to respond from home. In those cases, there won’t be enough issued rifles for all of us. Thus, I have mine ready for such emergencies and I have no qualms about putting the Primary Arms 1-8×24 into action if need be, within the ranges I know I have the ability to be accurate.

    You can see Primary Arms’ specifications at their website HERE. Or follow them on Facebook and Instagram.

    Primary Arms 1-8x scope review

    What do you think of the Primary Arms 1-8x ACSS scope? For those that already one, which load do you primarily use with it and what’s the longest shot you’ve made with yours?

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    Doug E

    Doug has been a firearms enthusiast since age 16 after getting to shoot with a friend. Since then he’s taken many others out to the range for their first time. He is a husband, father, grandfather, police officer, outdoorsman, artist and a student of history. Doug has been a TFB reader from the start and is happy to be a contributor of content. Doug can be reached at battleshipgrey61 AT, or battleshipgrey61 on Instagram.